Sorry man... not trying to rain on your parade here, but that job looks a bit rushed. You can make out a lot of scratches still there. It looks tons better, to be sure, but it's a ways off from being considered "polished".
500 grit is way too fine as a starting point and 1000 grit is much too bit of a jump from 500 grit.
You have to go step-by-step like ADC was saying. For my alternator I went through 220, 320, 400, 600, 800, and then 1000 grit paper. Wet sanding each time until the marks from the previous had been removed. I probably sanded for 15-20 minutes through each grade and the whole process took my about three hours.
Here's the starting point:
Even after the 220 grit, things looked bad:
This is just after finishing in the 1000 grit, getting ready for buffing:
And here's after brown tripoli on the buffing wheel (I skipped the black emery):
And this still isn't a "show quality" finish. I didn't have a spare flannel wheel to use with the rouge for a true mirror finish, but at this stage you can also use a chemical polish like mother's along with a microfiber cloth.